Department of Physics, Università Cattolica del Sacro Cuore, Brescia I-25121, Italy.
Nat Commun. 2011 Jun 14;2:353. doi: 10.1038/ncomms1354.
In strongly correlated systems the electronic properties at the Fermi energy (E(F)) are intertwined with those at high-energy scales. One of the pivotal challenges in the field of high-temperature superconductivity (HTSC) is to understand whether and how the high-energy scale physics associated with Mott-like excitations (|E-E(F)|>1 eV) is involved in the condensate formation. Here, we report the interplay between the many-body high-energy CuO(2) excitations at 1.5 and 2 eV, and the onset of HTSC. This is revealed by a novel optical pump-supercontinuum-probe technique that provides access to the dynamics of the dielectric function in Bi(2)Sr(2)Ca(0.92)Y(0.08)Cu(2)O(8+δ) over an extended energy range, after the photoinduced suppression of the superconducting pairing. These results unveil an unconventional mechanism at the base of HTSC both below and above the optimal hole concentration required to attain the maximum critical temperature (T(c)).
在强关联体系中，费米能级（E(F)）处的电子性质与高能标尺度的电子性质相互交织。高温超导（HTSC）领域的关键挑战之一是要理解与莫特型激发（|E-E(F)|>1 eV）相关的高能标物理是否以及如何参与凝聚态形成。在这里，我们报告了在 1.5 和 2 eV 处的多体高能 CuO(2)激发与 HTSC 之间的相互作用。这是通过一种新的光泵浦-超连续谱探测技术揭示的，该技术在超导配对被光诱导抑制后，提供了在 Bi(2)Sr(2)Ca(0.92)Y(0.08)Cu(2)O(8+δ)中扩展能量范围内介电函数动力学的访问。这些结果揭示了在达到最大临界温度（T(c)）所需的最佳空穴浓度以下和以上的 HTSC 基础上的一种非常规机制。
